Every construction site uses heavy vehicles like excavators and cranes, and they often have generators on site to provide power for essential project infrastructure, all normally fuelled by diesel. We estimate that this project will have used between 10,000 and 15,000 litres of fuel by the time of its completion, but we have dramatically reduced the associated carbon footprint by opting for biofuel. More specifically, hydrotreated vegetable oil (HVO), instead of traditional diesel. HVO is a second-generation biofuel, which means, unlike conventional diesel, it comes from a non-food bio-feedstock which doesn’t compete with the food chain. Because of the chemical makeup of HVO, the fuel is similar to conventional diesel, meaning it can be substituted for conventional diesel with little or no modification needed to the engines, it can be used to power heavy vehicles and generators. At the Whiteadder site, 20T mechanical excavators, tracked dumping machines and a steam roller all used Shell HVO biofuel throughout the project.
How is HVO produced?
HVO is produced by hydrotreating vegetable oils and fats – renewable materials which can be sustainably regrown when needed. To obtain HVO fuel from biomass, the biomass is gasified in a process called ‘pyrolysis’ where synthetic gas is created. The gas is then converted to liquid using a Fischer-Tropsch-like method. Biomass-to-liquid contains very few sulphur particles and aromatics, so they cannot be released during combustion in the engine. This lowers the fine particulate emissions. The cost of HVO compared to traditional diesel is around 30% higher, but it costs the planet far less, and it does exactly the same job. There is also no harmful smoke on start-up, improving air quality for those working on site.